sessionctx: fix a deadlock when set tidb_restricted_read_only = true

[Defined2014]

What problem does this PR solve?

Issue Number: close #55373, close #53822,

Problem Summary: follow #40283

What changed and how does it work?

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)

run shell below, reach more than 10000

count=0
while true; do
mysql -h 127.0.0.1 -P 4000 -u root -e "set global tidb_restricted_read_only = 1;set global tidb_restricted_read_only = 0;";
count=$((count+1))
echo "$count"
done

• No need to test

  • I checked and no code files have been changed.

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

None

[tiprow]

Hi @Defined2014. Thanks for your PR.

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[codecov]

Codecov Report

Attention: Patch coverage is 40.00000% with 3 lines in your changes missing coverage. Please review.

Project coverage is 75.1637%. Comparing base (bab3667) to head (6f1fc8c).
Report is 12 commits behind head on master.

Additional details and impacted files

@@               Coverage Diff                @@
##             master     #55407        +/-   ##
================================================
+ Coverage   74.9822%   75.1637%   +0.1815%     
================================================
  Files          1576       1577         +1     
  Lines        365580     443312     +77732     
================================================
+ Hits         274120     333210     +59090     
- Misses        71731      90020     +18289     
- Partials      19729      20082       +353     

Flag	Coverage Δ
integration	49.6104% <40.0000%> (?)
unit	72.2487% <40.0000%> (-1.7342%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Components	Coverage Δ
dumpling	52.9567% <ø> (-2.2327%)	⬇️
parser	∅ <ø> (∅)
br	52.5729% <ø> (+4.7546%)	⬆️

[Defined2014]

/retest

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-08-14 06:54:51.915812813 +0000 UTC m=+337376.619282451: ☑️ agreed by hawkingrei.
• 2024-08-14 08:23:42.352758852 +0000 UTC m=+342707.056228508: ☑️ agreed by CbcWestwolf.

[tiprow]

@Defined2014: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
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[easonn7]

/approve

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: CbcWestwolf, easonn7, hawkingrei

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[Defined2014]

/retest

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[Defined2014]

/retest

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[Defined2014]

/retest

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